The present invention relates to a machine tool. More particularly, it relates to a machine tool which has a table, a standard, a head part which moves on the standard relative to the table and accommodates a main spindle, an adjustable electric motor for driving the main spindle, and a tool changing arrangement including a tool transporting wheel adapted to align and couple the tool holder with the main spindle.
The machine tools of the above-described general type are known in the art. In a known revolving drilling machine tool described in the German Offenlegungsschrift No. 2,741,802, the tool holder is formed as a spindle gearing unit. With the introduction of the DC electric motor, only few spindle gearing units can be utilized, despite a wide range of rotational speeds. The head part is moved by its own drive unit. The known machine tools of this type possess some disadvantages in that they have a relatively complicated construction.